This invention is concerned with nut running tools of the non-impacting type for transmitting controlled torque to a driven article, such as a nut or bolt, by means of a succession of torque pulses. And its general objective is to provide an improved and practical air driven tool for this purpose.
The tool of the present invention includes a single blade air motor associated with a one-way clutch and operable to oscillate forwardly and reversely so as to deliver through the clutch to the work a succession of torque pulses in a predetermined direction. A torque responsive mechanism associated with a train of reduction gearing connecting the clutch with a final drive spindle cooperates, following delivery by the spindle of a final torque to the work, simultaneously with an air exhaust valve to stall the motor and with releasable latch mechanism to disconnect the drive of the motor from the work. Manipulative means is provided for regulating the torque value at which the torque responsive mechanism is to respond.
A general feature of the invention lies in the general organization and cooperative association of its components, whereby a flow of torque pulses is transmitted to run down the work, and whereby further pulse transmission is automatically terminated following setting of the work to a predetermined torque value.
A desirable advantage of a tool of this improved nature is the relatively small degree of reaction torque returned to the operator as compared with the high degree of torque delivered to the work.
Another feature of the invention lies in the particular structure and mode of operation of the air motor whereby the delivery of torque pulses to the work is achieved.
Another feature lies in the combination of this motor with a one-way clutch whereby the torque pulses are delivered to the work in a single direction and with a momentary time lapse between each pulse whereby the reaction torque returned to the operator is appreciably limited.
A further feature lies in the manner of association of the torque responsive mechanism with an air exhaust control valve and with a releasable latch connection in the drive train whereby, following delivery of a predetermined final torque to the work, the motor is caused to be stalled and simultaneously disconnected from the work.
A still further feature lies in a practical arrangement of manually adjustable means for regulating the torque value at which the torque responsive mechanism is to respond.
The foregoing and other objects, advantages, and features of this invention will appear more fully hereinafter from a consideration of the detailed description which follows, taken together with the accompanying drawings.